Aliphatic 2-oxa-1, 5-pentanediol diesters



FPaItentedwFeb. are, 11947 a 2,416,024 AIDHATIC Z-OXA-LS-PEN'IANEDIOL DIESTERS Murray Senkus, Terre Haute, Ind., assignor to Commercial Solvents'CorporatlomTerre Haute,

Ind., a corporation of Maryland No Drawing. ApplicatlonJune 2, 1944, SerialNo. 538.562

4 Claims. 260-488) 1 My invention relates-to novel 2-oxa-1,5-pentanediolialiphatic "diesters which can be produced bythe'sreaction of aliphatic acid anhydrides with :certain' 'dioxanes in accordance with the following equation:

Inthe formulas appearing above R represents an alkylgroup; R R R andR are substituents selected from the group consisting of hydrogen and e'alkyl; X is a member selected from the group consisting ofhydrogen and alkyl, andY is ra'mem'ber selected from the group consisting or hydrogen and a nitro'group.

The chief products, produced by the above re- .action'are the diesters of 2-oxa-1,5-pentanediols. LThere'are also formed in varying proportions, de- ':pending upon the cyclic formal concerned,equlv- 'alentamounts of 'diesters of' 1,3-propanedi'ols and '-2;6-dioxaheptanedio1s. .Thus, some 1 ,3-dioxanes :1yield'besides the 2-oxa'-1,5-'pentanediol diesters r'small amounts of 1,3-5propanediol diesters and .2g6-dioxal,7- heptanediol diesters. Moreover, it willz'bereadily. recognized that in instances where :the substituentsR'in the first formula shown, 3

2 One of the particularly surprising features of the process of my invention is the fact that only the cyclic formals when reacted with a suitable aliphatic anhydride are capable of producingthe diesters of the aliphatic 2-oxapentanediols.

Cyclic acetals formed from the higheraldehydes, such as acetaldehyde,'butyraldehyde, andthe like,

when treated with-acetic or similar anhydrides, yield only the plain diester, the acid corresponding to the anhydride, and a tar.

In practicing the process of my invention, a mixture consisting of cyclic formal, 'acidanhydride, and from about 1 to 5 per cent of a strong acid catalyst is heated until the esterification appears to' be complete. Thereafter a relatively small amount of a soluble salt of an aliphatic acid, preferably corresponding to the particular anhydride employed, is added to the solution'and is converted by the action of the'strong acld'catalyst, into a less ionized aliphatic acid thereby reducing the acidity of the reaction medium and preventing decomposition of the diester on subsequent distillation of the crude mixture. The latter is then filtered, the filtrate distilled under reduced pressure, and the purified diest'er collected.

In effecting the reaction described above,I have generally found it preferable to utilize a slight molecular excess of the acid anhydride. 'If the esterification appears to be somewhat'sluggish, the reaction can generally -be satisfactorily remedied by increasing slightly the amount of acid catalyst. As examples of catalyst that I have found suitable for use in my process, there may be mentioned p-toluenesulfonic acid, sulfuric acid, hydrochloric acid, and the like.

Cyclic formals which may be employed in car-- rying out my invention include 5-nitro-5-ethyl- 1,3-dioxane, 4,4,6-trimethyl-1,S-dioxane, 5,5-dimethyl-1,3-di0xane, 5-hydroxy-'1,3-dioxane, 1,3- dioxane, 5-nitro-1',3-dioxane, and the like.

In general, it may be said that any aliphatic acid anhydride will be found operative in my process under the conditions herein set i'orth, and therefore, I do not desire to be restricted to the particular acid anhydrides utilized in preparing the specific diesters mentioned below. Acid anhydrides suitable for use in'my process include acetic anhydride, propionic anhydride,-

butyric anhydride, valeric anhydride, stearicanhydride, and the like.

My invention may be more specifically illustrated by the following examples.

Example! A mixture consisting of 322 s. of 5-nitro-5- ethyl-1,3-dioxane, 204 g. of per cent acetic anhydride, and two drops of sulfuric acid was heated on a steam bath for three hours and thereafter was allowed to stand at room temperature over night. The mixture was then rectifled through a short Vlgreux column. As a re- 4 Included in the table which follows is a group of compounds prepared in accordance with the procedures outlined above together with certain physical properties of such compounds.

Table Analysis Boiling Ester C H point :1: m1

C. (mm.)

Galcd. Found Calcd. Found 8,6,5-trimethyl-2oxa-l.b-pentanedlol diacetate or 3,3,Hrimethyl-2-oxa-h5- pentanediol dlacetate or a mixture of the two above compounds 56.85 56.81 8.61 8. 37 112-114(3) 1. 0414 1. 4306 2,4-dimethyl-2-cxa-L4-butanediol diacetate 62.98 $.01 7.90 7.98 111(10) 1. 0676 1. 4212 suit of this distillation operation, there was obtained 89 g. of material boiling up to 133 C. (1 mm.) and 395 g. or 4-nitro-4-ethyl-2-oxa-1,5- pentanediol diacetate boiling at 133 C. (1 mm.) A 79 per cent conversion of the desired ester was obtained.

Analysis: Calculated for C H; NO N, 5.32; found-N, 5.77; d3, 1.1949; 11%, 1.4449.

Example I! To 352 g. of 1,3-dioxane, was added 430 g. of 95 per cent acetic anhydride and 0.4 g. of sulfuric acid. The temperature of the mixture rose to 115 C. in approximately three minutes. Thereafter the reaction mixture was heated on a steam bath for one hour after which time it was allowed to stand at room temperature for 15 hours. One g. of sodium acetate was then added to the solution and the mixture distilled through an emcient fractionating column. There was obtained, as a result of this distillation operation, 53 g. of a liquid having a boiling pant of 91-9? C. (10 mm.) and a saponification equivalent of 81 which compares favorably with the saponiilcation value of 80 fortrimethylene diacetate. The distillation also yielded 595 g. of 2-oxa-1,5-pentanediol diacetate boiling at 121-122 C. (10 mm.) "and 50 g. of a liquid boiling at 145-147 C. (10 mm.). Carbon and hydrogen analysis on the latter liquid indicated that it was 2,B-dioxa-1,7-heptanediol diacetate. The desired compound, 2-oxa-1,5-

pentanediol diacetate was obtained in a conversion or 78 per cent and analyzed as follows:

Analysis: Calculated for C H O -C, 50.52; H, 7found-C, 50.82; H, 7.34; d5, 1.1032; 11.1%,

The diesters of aliphatic 2-oxa-1,5-pentanediols of my invention are, in general, clear water- White mobil liquids having a pleasant ester-like odor. Such compounds serve as solvents for cellulosic as well as numerous other types of film'- iorming materials. Additional uses of these compounds will be evident to those skilled in the art.

' My invention now having been described, what I claim is:

1. As new compositions of matter, 2-oxa-1,5- pentanediol aliphatic diesters having the following general formula:

wherein R. is an alkyl group; RF, R, R and R are substituents selected from the'group consist.-

ing or hydrogen and alkyl; X is a member selected from the group consisting of hydrogen and alkyl; and Y is a member'selected from the group consisting of hydrogen and a nitro group.

2. 2-oxa-1,5-pentanediol diacetate.

"* 3. 4-nitro-4-ethyl-2-oxa 1,5, pentanediol diacetate.

4. 3-methy12-oxa-1,5-pentanediol dibutyrate.

MURRAY SENKUS.

nnrannucas orrnb The following references are of: record in the file of this patent:

UNITED STATES PATENTS Maclead "Jour. Chem. Soc. (Iondon) (1928) p. 3092. 

